Parametric estimation of ocean surface currents with HF radar

Hickey, K.; Khan, R.H.; Walsh, J.

doi:10.1109/48.376678

Cited by 25 publications

(8 citation statements)

References 14 publications

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“…However, when the two become closer, skeletons of the two will combine together, which can not be distinguished. At this moment, sea clutter should initially be suppressed or other characters of target should be made use of, such as the difference in the slope, instantaneous frequency changes and so on [15].…”

Section: Target and Sea Cluttermentioning

confidence: 99%

Low velocity target detection based on time-frequency image for high frequency ground wave radar

Yan

Wen

2007

Front. Electr. Electron. Eng. China

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The Doppler spectral broadening resulted from non-stationary movement of target and radio-frequency interference will decrease the veracity of target detection by high frequency ground wave (HFGW) radar. By displaying the change of signal energy on two dimensional time-frequency images based on time-frequency analysis, a new mathematical morphology method to distinguish target from nonlinear time-frequency curves is presented. The analyzed results from the measured data verify that with this new method the target can be detected correctly from wide Doppler spectrum.

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Section: Target and Sea Cluttermentioning

confidence: 99%

Low velocity target detection based on time-frequency image for high frequency ground wave radar

Yan

Wen

2007

Front. Electr. Electron. Eng. China

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“…So we adopt modern spectrum evaluation method (AR) [4] [5]. But the singular points in I/O signal don't remove totally, and the unbalance of I/O still needs to solve.…”

Section: Bragg-doppler Spectrum Identificationmentioning

confidence: 99%

“…SESAR post-processing system is shown as figure(4). It should be noted that satisfying the requirement needs improving computing speed.…”

mentioning

confidence: 99%

<title>Improvement of sea-environment sounding technology and signal processing method for HF ground-wave radar</title>

et al. 1998

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In the research of using HF ground wave radar to detect sea environment, we adopt symmetrical Yagi antenna array, correct the influence on antenna beam direction by platform on-sea and sea surface, optimize the schemes in the postprocessing, which include multiple correlation, Bragg-Doppler spectrum identification and reconstruction processing. During the signal gathering, the statistical character of slow sea-state variation is utilized (statistical big wave period about 5s). It facilitates the multiple correlation integration and satisfy the requirement for reconstruction processing. So the reliability of extracting sea echo data and articulation of Bragg-Doppler spectrum are greatly improved. We simulate how platform on-sea (made of Ferro-concrete) and sea surface influence beam direction with scale model. And under varied conditions the rise degree of main beam is measured. These data can help us correct the direction of vertical antenna during practical erecting. With these data, we do the inversion of sea surface flow field and wave field parameters. The result agrees with what the standard scaling machine measure.Company. It is set in the beam direction of 15km (locating by GPS). Comparing to the scaling, the current accuracy is 3 .lcmls, and the wave-height accuracy is 13.5% for SESAR synchronous measurement.Antenna is erected on the platform. The height of it from sea surface is about 714m (that is 0.62 -1.2 2), changing

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“…In accordance with [21], this contribution to the total clutter return can be modelled in the time-domain as…”

Section: B Surface Cluttermentioning

confidence: 99%

“…The assumption of "frozen" Bragg frequencies over Q consecutive PRI allows the clutter to be represented as superposition of complex sinusoids with fixed frequencies over each sub-CPI. Such a model has previously been adopted to parametrically estimate surface currents [21] and to cancel clutter over CPI lengths shorter than 3 seconds [23].…”

Section: B Surface Cluttermentioning

confidence: 99%

Non-stationary interference cancellation in HF surface wave radar

Fabrizio

Turley²

2003 Proceedings of the International Conference on Radar (IEEE Cat. No.03EX695)

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Abstract-High frequency (HF) interference in surface wave over-the-horizon (OTH) radars typically exhibits a time-varying or non-stationary spatial structure. Adaptive beamformers that update the spatial filtering weight vector within the coherent processing interval (CPI) are likely to suppress such interference most effectively, but the intra-CPI antenna pattern fluctuations result in temporal de-correlation of the clutter which severely degrades sub-clutter visibility after Doppler processing. A robust adaptive beamformer that effectively suppresses non-stationary interference without degrading sub-clutter visibility is proposed. The new algorithm is computationally efficient and suitable for practical implementation. Its operational performance is evaluated using experimental data recorded by the Iluka HF surface wave (HFSW) OTH radar, located near Darwin in far north Australia.

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Parametric estimation of ocean surface currents with HF radar

Cited by 25 publications

References 14 publications

Low velocity target detection based on time-frequency image for high frequency ground wave radar

Low velocity target detection based on time-frequency image for high frequency ground wave radar

<title>Improvement of sea-environment sounding technology and signal processing method for HF ground-wave radar</title>

Non-stationary interference cancellation in HF surface wave radar

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